Radial compressor and method for operating a radial compressor

Abstract

The invention relates to a radial compressor ( 1 ) comprising at least one impeller wheel ( 3 ), which is driven rotatably in a compressor housing ( 2 ) and has a wheel front side ( 5 ) and a wheel rear side ( 6 ), the wheel front side ( 5 ) being intended to convey a mass flow ( 13 ) by means of a number of blades ( 7 ), the wheel rear side ( 6 ) of the impeller wheel ( 3 ) having a blading ( 8 ) by means of which a second pressure distribution ( 12 ) is generated on the wheel rear side ( 6 ) of the impeller wheel ( 3 ) during operation of the radial compressor ( 1 ), which second pressure distribution counteracts a first pressure distribution ( 11 ) on the wheel front side ( 5 ) in order to reduce an axial force that is to be braced in the compressor housing ( 2 ). In order to functionally improve the radial compressor ( 1 ), in particular in respect of a use as air supply device in a fuel cell system, the compressor housing ( 2 ) is designed and is combined with the blading ( 8 ) on the wheel rear side ( 6 ) of the impeller wheel ( 3 ) such that, during operation of the radial compressor ( 1 ), a cooling air mass flow ( 14 ) is conveyed by means of the blading ( 8 ) on the wheel rear side ( 6 ) of the impeller wheel ( 3 ) in addition to the mass flow conveyed by means of the blades ( 7 ) on the wheel front side ( 5 ).

The invention claimed is: 
     
       1. A radial compressor ( 1 ) comprising at least one impeller wheel ( 3 ), which is driven rotatably in a compressor housing ( 2 ) and has a wheel front side ( 5 ) and a wheel rear side ( 6 ), wherein the wheel front side ( 5 ) is configured to convey a mass flow ( 13 ,  23 ) by a number of blades ( 7 ), wherein the wheel rear side ( 6 ) of the at least one impeller wheel ( 3 ) has a blading ( 8 ) by which a second pressure distribution ( 12 ) is generated on the wheel rear side ( 6 ) of the at least one impeller wheel ( 3 ) during operation of the radial compressor ( 1 ), which second pressure distribution counteracts a first pressure distribution ( 11 ) on the wheel front side ( 5 ) in order to reduce an axial force that is to be braced in the compressor housing ( 2 ), wherein the compressor housing ( 2 ) is combined with the blading ( 8 ) on the wheel rear side ( 6 ) of the at least one impeller wheel ( 3 ) such that, during operation of the radial compressor ( 1 ), a cooling air mass flow ( 14 ,  24 ) is conveyed by the blading ( 8 ) on the wheel rear side ( 6 ) of the at least one impeller wheel ( 3 ) in addition to the mass flow conveyed by the blades ( 7 ) on the wheel front side ( 5 ), wherein the radial compressor ( 1 ) comprises a separating apparatus ( 27 ) completely separating a fluid space containing the mass flow ( 23 ) on the wheel front side ( 5 ) from a fluid space containing the cooling air mass flow ( 24 ) on the wheel rear side ( 6 ) of the at least one impeller wheel ( 3 ), wherein the mass flow ( 23 ) and the cooling air mass flow ( 24 ) independently exit radially outward from the compressor housing ( 2 ). 
     
     
       2. The radial compressor according to  claim 1 , wherein the radial compressor ( 1 ) comprises an intake opening ( 28 ) radially within the blading ( 8 ) on the wheel rear side ( 6 ) of the at least one impeller wheel ( 3 ), through which opening the cooling air mass flow ( 14 ,  24 ), having passed through individual passages of the compressor ( 1 ), is conveyed out of the radial compressor. 
     
     
       3. The radial compressor according to  claim 1 , wherein the cooling air mass flow ( 24 ) conveyed by the blading ( 8 ) on the wheel rear side ( 6 ) of the at least one impeller wheel ( 3 ) during operation of the radial compressor ( 1 ) is sucked in and conveyed independently of the mass flow ( 23 ) conveyed by the blades ( 7 ) on the wheel front side ( 5 ). 
     
     
       4. A compressor housing ( 2 ), seal ( 25 ), and/or the at least one impeller wheel ( 3 ) for a radial compressor ( 1 ) according to  claim 1 . 
     
     
       5. The radial compressor according to  claim 1 , wherein the fluid space on the wheel rear side ( 6 ) of the at least one impeller wheel ( 3 ) is subjected to an ambient pressure. 
     
     
       6. The radial compressor according to  claim 1 , wherein the blading ( 8 ) on the wheel rear side ( 6 ) of the at least one impeller wheel ( 3 ) has a larger outer diameter ( 10 ) than the blades ( 7 ) on the wheel front side ( 5 ). 
     
     
       7. The radial compressor according to  claim 1 , wherein the separating apparatus ( 27 ) comprises a seal ( 25 ). 
     
     
       8. The radial compressor ( 1 ) according to  claim 1 , wherein, in addition to the mass flow ( 13 ) conveyed by the blades ( 7 ) on the wheel front side ( 5 ), the cooling air mass flow ( 14 ) is conveyed by the blading ( 8 ) on the wheel rear side ( 6 ) of the at least one impeller wheel ( 3 ) during operation of the radial compressor ( 1 ), which is used for cooling purposes ( 1 ). 
     
     
       9. A radial compressor ( 1 ) comprising at least one impeller wheel ( 3 ), which is driven rotatably in a compressor housing ( 2 ) and has a wheel front side ( 5 ) and a wheel rear side ( 6 ), wherein the wheel front side ( 5 ) is configured to convey a mass flow ( 13 ,  23 ) by a number of blades ( 7 ), wherein the wheel rear side ( 6 ) of the at least one impeller wheel ( 3 ) has a blading ( 8 ) by which a second pressure distribution ( 12 ) is generated on the wheel rear side ( 6 ) of the at least one impeller wheel ( 3 ) during operation of the radial compressor ( 1 ), which second pressure distribution counteracts a first pressure distribution ( 11 ) on the wheel front side ( 5 ) in order to reduce an axial force that is to be braced in the compressor housing ( 2 ), wherein the compressor housing ( 2 ) is combined with the blading ( 8 ) on the wheel rear side ( 6 ) of the at least one impeller wheel ( 3 ) such that, during operation of the radial compressor ( 1 ), a cooling air mass flow ( 14 ,  24 ) is conveyed by the blading ( 8 ) on the wheel rear side ( 6 ) of the at least one impeller wheel ( 3 ) in addition to the mass flow conveyed by the blades ( 7 ) on the wheel front side ( 5 ), wherein the radial compressor ( 1 ) comprises a separating apparatus ( 27 ) completely separating a fluid space containing the mass flow ( 23 ) on the wheel front side ( 5 ) from a fluid space containing the cooling air mass flow ( 24 ) on the wheel rear side ( 6 ) of the at least one impeller wheel ( 3 ), wherein the blading ( 8 ) on the wheel rear side ( 6 ) of the at least one impeller wheel ( 3 ) has a larger outer diameter ( 10 ) than the blades ( 7 ) on the wheel front side ( 5 ). 
     
     
       10. The radial compressor according to  claim 9 , wherein the radial compressor ( 1 ) comprises an intake opening ( 28 ) radially within the blading ( 8 ) on the wheel rear side ( 6 ) of the at least one impeller wheel ( 3 ), through which opening the cooling air mass flow ( 14 ,  24 ), having passed through individual passages of the compressor ( 1 ), is conveyed out of the radial compressor. 
     
     
       11. The radial compressor according to  claim 9 , wherein the cooling air mass flow ( 24 ) conveyed by the blading ( 8 ) on the wheel rear side ( 6 ) of the at least one impeller wheel ( 3 ) during operation of the radial compressor ( 1 ) is sucked in and conveyed independently of the mass flow ( 23 ) conveyed by the blades ( 7 ) on the wheel front side ( 5 ). 
     
     
       12. A compressor housing ( 2 ), seal ( 25 ), and/or the at least one impeller wheel ( 3 ) for a radial compressor ( 1 ) according to  claim 9 . 
     
     
       13. The radial compressor according to  claim 9 , wherein the fluid space on the wheel rear side ( 6 ) of the at least one impeller wheel ( 3 ) is subjected to an ambient pressure. 
     
     
       14. The radial compressor according to  claim 9 , wherein the separating apparatus ( 27 ) comprises a seal ( 25 ). 
     
     
       15. The radial compressor ( 1 ) according to  claim 9 , wherein, in addition to the mass flow ( 13 ) conveyed by the blades ( 7 ) on the wheel front side ( 5 ), the cooling air mass flow ( 14 ) is conveyed by the blading ( 8 ) on the wheel rear side ( 6 ) of the at least one impeller wheel ( 3 ) during operation of the radial compressor ( 1 ), which is used for cooling purposes ( 1 ).